卫星遥感温室气体的大气观测技术进展

全球、区域及城市的碳浓度、碳源汇信息是应对气候变化、达成双碳目标、完善国际谈判、支持治理政策制定与执行的重要依据。国际认可的“自上而下” 方法将卫星观测作为基础的通量计算技术, 是验证温室气体排放清单的重要手段。系统介绍了温室气体的卫星探测载荷原理、类别和发展, 以及反演、估算CO2、CH4 和N2O 的浓度和排放通量的方法, 还有探测缺失和误差存在的影响因素等; 分析了对卫星探测温室气体能力提高的迫切需求, 浓度反演和排放量估算精度不足, 以及N2O、氟化物等其他温室气体遥感研究缺乏、地基遥感验证能力薄弱等问题; 最后总结了我国温室气体卫星遥感技术的发展趋势, 主要是面向主被动高时空分辨率卫星的研制应用、高精度多尺度排放量估算(特别针对城市、小区域和点源尺度)、氟化物遥感评估等主题, 以加强对碳排放的量化观测, 并增强对碳循环的理解, 提高感知和应对气候变化的能力。

Advances in atmospheric observation techniques for greenhouse gases by satellite remote sensing

In response to climate change, the information of global, regional and urban carbon concentration, as well as carbon source and sink is essential for achieving dual carbon goals, actively participating in international negotiations, and providing policymakers with reliable and up-to-date support. The “top-down” approach to carbon source-sink accounting, which uses satellite observations as the base flux calculation technology, has become an internationally recognized method for supporting and validating greenhouse gas emissions inventories. This paper systematically introduces the principle, category and development of the satellite detection payloads for greenhouse gases, the atmospheric remote sensing estimation methods for CO2, CH4, and N2O concentrations and emission fluxes, as well as the influencing factors of detection deficiency and errors. And the urgent demand for improving the detection capability of satellites for greenhouse gas, the insufficient accuracy of concentration inversion and emission estimation, the lack of remote sensing research on other greenhouse gases such as N2O and fluoride, and the weak verification capability of ground-based remote sensing are analyzed in depth. Finally, the future development trends of greenhouse gas satellite remote sensing technology in China are summarized, which are mainly focusing on the development and application of active and passive, high temporal and spatial resolution satellites, high-precision emission estimation (especially for cities, small areas and point source scales), and remote sensing assessment of fluoride, in order to promote the understanding of carbon cycle, and improve the ability to sense and respond to climate change.